I love it and I think I was nominated as the resident LINK fanboy. I think it's because I bought some at around $0.42 and then sold a portion at $49.22.
Anyway, it's a great project that fills a real need. Chainlink provides a decentralized oracle to serve as blockchain middleware. Current smart contracts can't communicate with external resources (e.g. something off chain). In order to do that, the smart contract creator either needs to do a pile of additional development or they need an intermediary. That's where Chainlink comes in. It provides oracle data that can be queried by anyone writing a smart contract. They no longer need to know how to interface with off chain data. All they have to do is query a Chainlink oracle to get their off chain data.
Think of it this way. Let's say you were writing an app similar to the Uber app. Instead of creating a payment gateway, you just call the Visa / Mastercard API for payment details. Instead of having to map the planet, you just call on the Google Maps API for map data and on and on.
That's what LINK does. It fills that gap so smart contract programmers only have to worry about their contract and nothing off chain.
The nice part is that there are tons of nodes that are rated based on SLA (uptime), Latency (response time) and Correctness (deviation of data from their piers). Nodes with invalid / molested / altered data are dumped from the network. That keeps someone from attacking a single node in an attempt to attack a smart contract, which is something that has happened with centralized oracles.